<div class="red">
    Red
</div>
<div class="yellow">
    Yellow
</div>
<div class="blue">
    Blue
</div>
div {
    height: 100px;
    width : 100px;
    border: 1px solid;
    position:absolute;
}

.red{
    background-color:red;
    z-index:-1;
}

.yellow{
    background-color:yellow;    
    left:20px;
    top:20px;
    z-index:0;
}

.blue{
    background-color:blue;  
    left:40px;
    top:40px;
    z-index:-1;
}

External CSS

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External JavaScript

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